Field of the Disclosure
Embodiments of the present invention relate to an organic light emitting diode display device and a method for manufacturing the same, and more particularly, to an active type organic light emitting diode display device and a method for manufacturing the same.
Discussion of the Related Art
With the advancement of an information-oriented society, there is an increasing demand for display devices which display information. Especially, a cathode ray tube (CRT) having a simple driving method and a reasonable price was widely used in an early stage of the display device, thereby enabling popularization of the display device. Thereafter, a liquid crystal display (LCD) device capable of realizing full colors and wide viewing angle was used as a substitute for CRT. Recently, an organic light emitting diode (OLED) display device has been attracted as a next-generation flat panel display.
Owing to various advantages such as high resolution, thin profile and low power consumption, there is an active study for the OLED display device regarded as the next-generation flat panel display, and more particularly, for the large-sized OLED display device.
FIG. 1 is a cross sectional view illustrating some parts of the related art OLED display device.
As shown in FIG. 1, the related art OLED display device may include a substrate 101, an anode electrode 110, an organic light-emitting layer 120, a cathode electrode 130, a sealing layer 140, and a color refiner 150.
First, the anode electrode 110, the organic light-emitting layer 120 and the cathode electrode 130 are sequentially formed on the substrate 101. The anode electrode 110 supplies a hole to the organic light-emitting layer 120, and the cathode electrode 130 supplies an electron to the organic light-emitting layer 120. Thus, when exciton, which is generated by the supplied hole and electron, falls to a ground state from an excited state, light is emitted so that the emitted light is supplied to display an image on a screen of the OLED display device.
FIG. 1 shows the OLED display device of WRGB method with the color refiner 150 for converting a color of white color light into red, green and blue colors corresponding to the three primary colors. The color refiner 150 is formed on the sealing layer 140 above the cathode electrode 130, and the color refiner 150 may not be formed in the pixel for emitting the white color light.
Especially, the organic light-emitting layer 120 may include one or more light-emitting layers, and the organic light-emitting layer 120 may emit the white color light obtained by mixture of red, green and blue colors.
Meanwhile, the OLED display device is configured to have a multi-layered thin film structure, whereby a large amount of light loss might occur in the interface between each layer. In order to overcome this problem and to improve light extraction efficiency, a microcavity structure may be applied to the OLED display device. The microcavity structure indicates a reflection structure which satisfies an optical distance corresponding to an integer multiple of half-wavelength of the light emitted by each pixel. In this reflection structure, the light reflection is repeated so that the light is amplified by constructive interference, whereby the amplified light is emitted to the external, thereby improving light efficiency as compared to the related art.
However, when the white color light emitted by the organic light-emitting layer 120 including the plurality of light-emitting layers is amplified through the microcavity structure, and is then emitted to the external, the color of light may be changed according to a viewing angle due to a plurality of peak wavelengths.